Signal lantern



J. C. STIMSON SIGNAL LANTERN Original Filed Dec. 10. 1923 Sept. 20, 1932.

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i Patented Sept. 20, 1932 i JONATHAN CASS STIMVSON, F ST. LOUIS, MISSOURI SIGNAL LANTERN riginal application led December 10, 1.923, Serial No. 679,724. Divided and this application led September 5,- 1930.

This invention relates to light signals, and more particularly to signal lanterns and 'cover glasses therefor. This application is a division of application Serial No. 67 9,7 24,

filed December 10, 1923.

Traffic movement at night is universally dependent for its safety upon the display of signal lights'used either to indicate the location of vehicles themselves, which .comprise 1;) the traffic, or to give interpretive indications for the control of the trafiic movement. Sig nal lanterns are the specific agent employed for furnishing the light indication. In spite of the greatest care in the design of lantern equipment and its maintenance, failures frequently occur, even when the signalling system is highly developed 'as in railroad service.

in the case of highway trafiic the lantern 29 signals required for safety are largely confined to proper lights marking the location of automobiles. Automobiles are generally equipped with electric signal lanterns which are efficient for the purpose, but failures are numerous. Bulbs frequently burn out and electrical connections become faulty. Repairs are easily made, but because of widespread individual ownership and operation it is impossible to enforce the prompt atten- 31.) tion which the failure warrants. The menace to safety resulting is not inconsiderable. Also the failure may occur when the automobile is in use and the driver is unaware of the failure. This 'is especially true of the rear marker which is usually required 'by law to be a red signal lantern.

Signal lanterns, wherever used, and with any type of light source, are provided wit-h a transparent cover or glass, which protects the light source from the weather, is a transparent medium for the transmission of the light toward the bpoint of observation, and which may impart color to the signal light source. This cover may also be in the form of a condensing lens for the purpose of colleeting the rays from the source in the formof an intensified beam projected in the direction from which it is to .be observed. In highway traffic signals empoying a lamp a condensedsignal beam is not necessary as an serial No. 479,814.

ordinary light is ordinarily seen at a sufficient distance for safety. In other service employing a lamp signal a condensed beam is not always necessary; the light should not, however, be dimmed more than necessary.

In Patent Nos. 1,671,086, granted May 22, 1928, and 1,743,834, granted January 14, 1930, are described reflecting devices adapted for use in tail lights for automobiles, which are constructed and arranged to redect external light incident thereon at varying angles from a distant source back in the general direction of the light source. These reectors also have means adapted to spread the light with substantial uniformity throughout their field of spread in order to direct a spreading beam or beams back towards and visible to an observer located a substantial distance outside of the line connecting the refiector with the light source. 1n one of the embodiments described in Patent No. 1,671,086, the reflector comprises a glass plate having a series of triple reflecting units arranged in contiguous relation to form a reflecting area withthe reflecting surfaces of each unit arranged in a circuit about the axis thereof.y While this reflecting plate is adaptable for use in a'tail light cover glass and lens, in that it is transparent, so asv to permit light from the lamp in the casing to issue therefrom and through the reflector, some of the light will be refracted to such an extent as to aect visibility from a distance.

One of the objects of this invention, therefore, is to provide a reflecting signal in which a series of reflecting units are constructed and arranged to form a reflecting area but with a series of distributed free light transmitting zones, each of substantial area, between the units.

Another object is .to provide a signal lantern which although provided with a cover glass or lens adapted to refiect light incident thereon from a distant source back in the general direction of the light source, is, nevertheless, so constructed and arranged as to permit light from the lamp to issue freely through the reflector substantially throughout its refiecting area.

Further objects will appear from the detail description taken in connection with the accompanying drawing, in which- Figure 1 is a face viewof a reflector embodymg this invention; ,A

Figure 2 is a section on the line 2 2 of Figure 1;

Figure 3 is a vsectional view. of a signal lantern embodying this invention;

Figure 4 is a View similar to Figure 1, but showing another embodiment of this invention; and c Figure 5 is a section on the line 5 5 of Fi re 4.

enerally stated in accordance with this invention, the reflecting signalcomprises a s eries of reflecting units constructed and arranged to form a reflecting area with a series of distributed free light-transmitting zones between these units. In accordance with one embodiment of this invention, the reflecting units are arranged in contiguous relation to form the reflecting area and the continuity of these units is Ainterrupted to provide a series of distributed free light-transmitting zones between these units. In accordance with an embodiment of this invention, the signal comprises a glass plate having a series of total reflecting units preferably arranged on one face thereof and arranged to reflect light incident thereon from the other face. These units are constructed and arranged to reflect external light incident thereon at varying angles from a distant source back in the general direction of the light source, and

. means is also provided adapted to spread the light reflected by these units with substantial uniformity throughout its field of spread in order to direct spreading beams back towards and visible to an observer located a substantial distance outside of the line connecting the reflector with the light source. In accordance with an embodiment of this invention, each of these units has reflecting surfaces constructed and arranged to multiply reflect the external light; these reflecting surfaces, in the embodiment shown and described, being arranged in a circuit about the axis of each unit. In a signal lantern employing this reflector, the latter is so constructed and arranged as to permit light from the lamp-to issue from the casing through the reflector, and in accordance with an embodiment of this invention, this reflector is in the form of a transparent plate provided with reflecting units; these units, however, being interrupted to provide a series of distributed i light transmitting zones therebetween for the free transmission of the light from the-lamp. Referring to the accompanying drawing, and more particularly to Figures 1, 2 and 3, 2 designates the casing of a signal lantern, which, as shown, is provided with a lamp 3 and a cover glass 4, held in place by a ring 40, in the usual manner. In the embodiment shown, the signal lantern is a .so-called tail light of an automobile and is 'provided with an attachment 41, whereby it may be ,secured in place; it is to be understood, however, that this is for the purpose of illustrating a practical application ofthis invention; for the invent1on is applicable to signal lanterns generally and is evenpf general application.

The cover glass or plate 4 is arranged in the lantern aperture in front of the lamp and is constructed and arranged not only to permit the lightto pass therethrough, but also to'reflect external light impinging thereon from a distant source back in the general direction ofthe source. In the embodiment of the invention shown, the glass plate 4 is generally of the construction and arrangement shown in Patent No. 1,671,086, and it may be produced as there described or as more particularly described in Patent No. 1,591,- 572, granted July 6, 1926. As shown, it comprises a series of triple reflecting units 1 arranged in contiguous relation on the back of the plate facing the lamp, so as to form a reflecting area, and where this plate is of glass, as shown, these units are total reflecting. The patents referred to describe not only the action of reflecting external light incident on the reflector at varying angles from a d1stant source back in the general direction of the light source, but they also describe the action of spreading the light reflected by the units with substantial uniformity throughout its field of spread in order to direct spreading beams back to and visible to an observer located a substantial distance outside of the line connecting the reflector with the light source.

From a consideration'of Figure 3, it will be seen that beams such as 100 and 102, incident normal or at an angle to the reflector will be reflected back to the light source; for simplicity sake, the spreading beam effect has not been shown, but this is fully shown and described in the patents referred to. When we now consider light emanating from the lamp, it will be seen that a beam 101 normal to the reflector will pass therethrough without refraction; a beam such as 109, however, striking one of the reflector units, as shown, will be sharply'refracted; accordingly, where the reflector is constructed as shown in Patent No. 1,671,086, the light issuing through the reflector is refracted so as to affect distance visibility within the usual zone of. observance.

In accordance with .this invention, and as shown in the drawing, the reflecting units or prisms on the back'of the cover glass or plate are interrupted to form a series of distributed lee light-transmitting zones. As shown in Figures 1, 2, and 3, the glass is provided with zones 5 inserted at the points of juncture of groups of six units', each zone being in the form of a six sidedhead or facet having a of an hexagon with the triangular portion outside of the hexagon portion inactive for reflection. By providing the facets with faces parallel to the front face, these particular zones in the cover glass transmit light from source3 in the same manner as an unigured cover glass or window, and reinforce the intensity of the signal beam if that is necessary. Beams emanating from the lamp 3 and passing through two of these facet portions 5 are shown at 111 and 112.

lin Figures 4 and 5, the reecting units 1() have hexagonal contours, as well as hexagonal apertures and form a continuously active area or face which will appear uniformly illuminated. in this caseysince all of the area is effective for reection, free lighttransmitting zones are provided by truncating the apices of the reecting units, as shown at 50. While this reduces the reflecting eiliciency in the ratio that the area of the plane facets formed by truncation bears to the entire reflecting area, this is compensated by the fact that free light-transmittinggzones are provided.

lt will thus be seen that the invention accomplishes its objects. Not only is there provided a reflecting signal which will reflect light incident thereon from a distant source and back in the general direction of the light irrespective the limits) of the angle of incidence; but the reflector is so constructed as to permit free transmission of light therethrough in zones distributed substantially throughont'the reflecting area. Where the reflector is employed in a signal lantern,

it will remain effective as a warning signal;

for the light of an approaching vehicle impinging upon the cover glass will be reflected back to its source, and particularly to the driver of the vehicle, so as to give a Warning signal.

While the invention is particularly applicable to the general type of reector specifically shown and described, it will be understood that the invention is applicable in many cases to other types of reflectors, and particularly other than triple reflectors. Moreover,` while the invention is particularly applicable to,

glass reflectors, it will be understood that the terms are used descriptively and not limitatively; and, as described in Patents No. 1,671,086 and No. 1,743,834, the reflectors may be of the metallic or silvered type.

lt will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations; that is contemplated by and is within the scope of the ap pended claims. It is furthermore obvious that various changes may be made in the details of construction, within the scope of the appended claims, without departing from the spirit of this invention. It is, therefore, to be` understood that this invention is not to be limited to the specific details shown and/or described.

Having thus described the invention what is claimed is:

1. A reflecting signal, comprising a series of reflecting units arranged in contiguous relation to form a -rellecting area, the continuity of said units being interrupted to provide a series of distributed free lighttransmitting zones, each of substantial area, between said units.

2. A reflecting signal, comprising a glass plate having a series of total reflecting units arranged in contiguousrelation on one face thereof arranged to reflect light incident thereon from the other face, the continuity of said units being interrupted to provide a series of distributed free light-transmitting zones, each of substantial area, between said units.

3. A reflecting signal, comprising a series of reflecting umts constructed and arranged in contiguous relation to form a reflecting area, the continuity of said units being interrupted to form a series of distributed free light-transmitting zones, each of substantial area, between said units, each of said unitsbeing constructedfand arranged to refleet external light incident thereon at varying angles from a distant source back in the general direction of the light source.

4. A reecting signal, comprising a series of reflecting units constructed and arranged in contiguous relation to form a reflecting area, the continuity of said units being interrupted to form a series of distributed free light-transmitting zones, each of substantial area, between said units, each of said units being constructed and arranged to reflect external light incident thereon at varying angles from a distant source back in the general direction of the light source, said signal having means adapted to spread the light reflected by said units with substantial uniformity throughout its field of spread in order to direct spreading beams back towards and visible to an observer located a substantial distance outsidel of a line connecting the signal with the light source.

p 5. A reflecting signal, comprising a series of reflecting units constructed and arranged in contiguous relation to form a relecting area, the continuity of said units being interrupted to form a .series of distributed free light-transmitting zones, each of substantial area, the continuity of said units being in a circuit about the axis thereof constructed and arranged to multiply reflect external light incident thereon dat varying angles from a distant source back in the general direction of the light source. r

7.' A reflecting signal, comprising a glass plate having a series of reflecting units in contiguous relation on one face thereof arranged to reflect light incident thereon from the other face, the continuity of said units being interrupted to form a series of distrib` uted free light-transmitting zones, each of substantial area, between the bases of said units.

` '8. A reflecting signal, comprising a glass plate having a series of reflecting units on one face thereof arranged to reflect light in' cident thereon from the other'face, the continuity of said units being interrupted to form a series of distributed free light-transthe apices of said units.

9. A signal lantern, comprislng, a casing, a lamp therein, and a reflector associated with said lamp to' permit light from said lamp to issue from said casing through said reflector, said reflector having a series of reflecting units constructed and arranged in contiguous relation to form a reflecting area for external light incident thereon from a distant source, the continuity of said units being interrupted to form a series of distributed free light-transmitting zones, each of substantial area, between said units.

10. A signal lantern, comprising, a casing, a lamp therein, and a reflector associated with said lamp to permit light from said lamp to issue from said casing through said reflector, said reflector having a series of reflecting units in contiguous relation and forming a reflecting area, the continuity of said units being interrupted to form a series of distributed free light-transmitting zones, each of substantial area, between said units, said units being constructed and arranged to reflect external light incident thereon at varying angles from a distant source back in the general direction of the light source. 11. A signal lantern, comprising, a casing, a lamp therein, and a reflector associated with said lamp to permit light from said lamp to ismitting zones, each of substantial area, at

sue fromsaid casing through said reflector,

said reflector havingaseries of reflecting units in contiguous relation and forming a reflecting areaq the continuity of said units bein interrupted to form a series of ydistribute free light-transmitting zones, each of substantial area, between said units, said units being constructed and arranged to reflect ex` ternal light incident thereon at varying angles from a distant source back in the eneral direction of the light source, said re ector having means adapted to spread the light reflected by said units with substantial uniformity throughout its lield of s read in order to direct spreading beams haag towards and visible to an observer located a substantial -distance outside of a line connecting the signal with the light source.

12. A signal lantern, comprising, a casing, a lamp therein, and a transparent plate associated with said lamp to permit light from said lamp to issue from ,said casing through said'plate, said plate having a series of reflecting units constructed and arranged in contiguous relation to form a reflecting area for external light incident thereon from a distant source, the continuity of said units being interrupted to form a series of distributed free light-transmitting zones, each of substantial area, between said units.

13. A signal lantern comprising, a casing, a lamp therein, and a transparent reflector on saidcasing in front of said 'lampl said reflector having totally reflecting surfaces on the back thereof and in front of said lamp, said surfaces being interrupted to form a series of distributed light-transmitting zones each of substantial area in order to permit light from said lamp to issue freely from said casing, said reflecting surfaces being constructed and arranged to reflect external light incident thereon at varying angles from a distant source back in the general direction of the light source, and said reflector having means adapted to slightly spread the reflected light with substantial uniformity throughout its field of spread in order to direct a spreading beam back towards and visible to an observer located a substantial distance outside of a line connecting the reflector with the light source. y

14. A signal lantern comprising, a casing, a lamp therein, and a transparent reflector on said casing in front of said lamp, said reflector having totally reflecting units on the back thereof and in frontof said lamp, said units having spaces therebetween to form a series of distributed light-transmitting zones each of substantial area in order to permit light from said lamp to issue freely from said casing between said units, said units having reflecting surfaces constructed and arranged to reflect external light incident thereon at varying angles from a distant source back in the general direction of the light source, and

said reiector having means adapted to slight- 1y spread the light reflected by the surfaces of the several units With substantial uniformity throughout their fields of spread inorder to direct spreading beams back towards and visible to an observer located a substantial distance outside of a line connecting the reflector with the light source. l

In testimony whereof, I aix my signature.

' JONATHAN CASS STIMSON. 

